Is there a way to reduce the blur caused by denoising while still reduce noise
The blur is an artifact of how denoising is performed. It can't always be totally removed, but can be controlled to a certain extent by adjusting the Denoising parameters found in the Render Layers Tab of the Properties window.  In the next screen shot I have moved denoise to the top of the tab. It is usually farther down.



The Diffuse, Glossy, Transmission and Subsurface parameters are flags that tell the denoiser to use those types of rays in calculating the replacement pixels. You can experiment with them to see if they help.

The Radius parameter sets the area of pixels around the pixel being denoised to consider when calculating the replacement color.

The strength parameter controls how much to consider the surrounding pixels.

The feature strength parameter controls the number of passes over the image the denoiser makes.

If you hover over each parameter it will give a brief summary of the effect caused by that parameter.